Ribbon feeding and reversing mechanism for typewriting machines



Nov. 28, 1950 c. w. CRUMRINE 2,531,872

RIBBON FEEDING AND REVERSING MECHANISM FOR TYPEWRITING MACHINES Filed Dec. ,18, 1947 FIGJ ATTORNEY Patented Nov. 28, 1950 RIBBON FEEDING AND REVERSING MECH- ANISM FOR TYPEWRITING MACHINES Chester W. Crumrine, Rochester, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application December 18, 1947, Serial No. 792,403

Claims.

This invention relates to typewriting machines and more particularly to ribbon feeding and reversing mechanism.

An object is to provide a ribbon feeding and reversing mechanism in which the ribbon spools may be inserted and removed more readily than the ones in ribbon mechanisms hitherto used in the art. v 7

An object is to provide a ribbon feeding mechanism in which the ribbon spool is frictionally driven at the rim.

An object is to provide an improved reversing mechanism.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. l is a plan view of the ribbon mechanism.

Fig. 2 is a vertical section on the line 2-2 in Fig. 1 and shows the left-hand ribbon feeding unit in side elevation.

Fig. 3 is a vertical section on the line 3--3 in Fig. 1.

Fig. 4 is a front elevation of the left-hand ribbon feeding unit and shows the reversing mechanism in disengaged position. I t

Fig. 5 is a view similar to Fig. 4, but showing the reversing mechanism in engaged position.

Fig. 6 is a side elevation of a portion of the reversing mechanism associated with the righthand and left-hand ribbon feeding units.

In Fig. 1 there is shown pair of ribbon feeding units which are mirror images of each other in respect to placement of parts and, the rightof which the web l4 forms the connecting part.

The frame comprising the plates II and I2 is mounted in any suitable manner on a frame member [5 by means of which the ribbon mechanism may be mounted as a unit removable from the machine, this frame being provided with suitable lugs l5a. for the purpose of securing the frame [5 to the main frame work of the machine, not

shown.

. Journaled in the frame plates and 12 of both units is a drive shaft l6 which, at its right-hand end (Fig. 1), is provided with a bevel gear l8a meshing with a bevel gear IS on the shaft I9 suitably journaled in a lug Ila. formed in the plate II for the right-hand unit RH. The shaft I9 may be driven in any suitable way known in the art as, for example, by gearing to the spring drum which powers the carriage of the typewriting machine so that the shaft [9 always rotates counterclockwise (Fig. 1) when the carriage moves in a letter spacing direction. Between the frame plates H and [2 of both units the shaft [6 is provided with friction drive rollers I! which, by cooperation with the edges of the ribbon spools, efiecta counterclockwise movement of the spools.

The spaces between the plates II and I2 form pockets for the reception of the right-hand ribbon spool 20R and the left-hand ribbon spool ML and, for the purpose of supporting the ribbon spools in the pocket and also rotatably mounting them in coaction with rollers l'l, there is provided a loose roller 2| for each unit which is rotatably mounted on a stud 22 riveted to the plates H and I2 in each case. The rollers 2| are spaced from the driving rollers I! a distance slightly less than the diameter of the ribbon spools 20R and 20L.

Journaled on the plate I2 at IZa (Figs. 2 and 3) is a lever 23, one arm of which is provided with a stud 23a. carrying the roller 24 and the longer arm of which is similarly provided with another stud 23b and roll-er '25. When the ribbon spool is inserted in the pocket between the plates II and I2 as in Figs. 2 and 3, the rims thereof cooperate with the rollers l1, 2|, and 24 whereby rotation of the roller l'l will drive the ribbon spool 20L in a clockwise direction.

For the purpose of holding the rims of the ribbon spool 20L in engagement 'with the roller ll, there is provided a spring 26 (Fig. 2) which is anchored to the lever 23 and to a pin carried by the plate l2. The effect of the spring 26 is to cause roller 24 to wedge the spool 20L downwardly between the rollers l1 and 2|, the roller 25 only lightly engaging the rims of the ribbon spools, if at all. The primary purpose of the roller 25 is to push the spool upwardly when it is desired to remove it or stop feeding by that spool and for this purpose a separate mechanism now to be described is provided. Both ribbon feeding units are provided with arms 23, rollers 24, 25, and springs '25.

The lever 23 for the left-hand unit is connected by a, link 21 to a finger lever 28 and the lever 23 for the right-hand unit is connected by a link 21a to one arm of a bell crank 28a (Fig. 6), both levers 28 and 28a being secured to the cross shaft 29 journaled in the plates l2. The lever 28 projects through a suitable slot in the frame 25 (Fig. l) and a slot in the outer casing of the machine and may be grasped by the operator and lifted. When this is done, the link 21. is pushed upwardly (Figs. 2 and 6) and rocks the left.- hand lever 23 clockwise (Fig. 2) whereby the roller 25 pushes up the left-hand ribbon spool 20L to stop feeding this spool or tofacilitate its removal for the purpose of inserting a new ribbon. At the same time, link 21a, is pulled downwardly allowing the spring 25 for the right-hand spool to. rock the associated lever 26 clockwise with reference to Fig. 2 and engage the right-hand spool 20R. with the right-hand roller I1.

Normally only one of the roliers 11 engages a ribbon spool and they are automatically selectively engaged with the ribbon spools, on one side or the other of the machine, to feed one or the other of the ribbon spools. The levers 28., 28a. control the reversing of the ribbon by liftingone orthe other of the ribbon spools 20L, 2BR far enough tov disengage the roller I? from the spool which is to be idle and pushing down the other spool into engagement. with the other roller. Lever 28 provides a means. of re.- versing the ribbon manually when necessary.

2, 3, and 6 show the condition of the parts when the leftehand spool is feeding with the left-hand lever 23 rocked counterclockwise as as it will go whereby the roller 24 wedges the ribbon. spool 20L between the left-hand rollers H and 2-H. ciated with the right hand unit RH (Fig. 1), under these conditions, forms a straightened toggle with link 2m whereby, when the arm 28 is raised, the lever 23 associated with the lefthand spool is rocked clockwise (Figs. 2 and 3 to disengage the spool ZtL from its driving roller t1, and; the arm 28a, by pulling down the link 2-10; ion theright-hand unit RH, rocks the lever nthereior in a counterclockwise direction, considered with reference to Fig. 2, to wedge the right-hand spool 201% between the right-hand rollers I1 and 2|.

The lovers- 2 28a and shaft 29 are automaticat-1y shifted to eiiect reversal in the feeding of the ribbon; by means of two links 30, 300, the link 39 being associated with the lever 28 and the link 30a associated with the lever 28a and respectively loosely pivoted thereto so as to permitlateral movement of the links on the levers. The link 39 associated with the left-hand spool 20L is curved around the shaft Hi and at its upper end has a reduced portion loosely received a hole or eye formed in one arm of a bell o-r-an-k 31f pivoted at 12d on a lugl2c formed in the plate 'l-zof the left-hand spool 20L. The other arm of the bell crank 3i projects into the plane of a control lever 32 pivoted at [2e on; the plate l2. The lever 32 is formed with the usual off-set lug 32a having a suitable slot through which passes the ribbon as it unwinds from the leit-handspool 20L. The control lever 3 2- is urged in a counterclockwisedirection by a spring33 anchored to the same pin as the spring 28'. The bell crank Si is urged in a clockwise direction bya spring 3la which maintains contact between lever 32 and lever 3|, but spring 33 is stronger than spring 3|. Link 30 is provided' with a roller 30-11 which is out of the plane of, but below, the level of the teeth of a star wheel 34 secured to the shaft 16.

The righ-thand unit 20R isprovided with exhausted, the tension built up in the ribbon The lever 28a which is asso-.

R ultimately will cause the control lever 32 for the. right-hand spool to rock clockwise with reference to Fig. 2 and allow the bell crank 31 for the right-hand spool (Fig. 1) to rockcounterclockwise under the influence of its spring, thereby placing the roller 3% for the right-hand link 39a in the path of the teeth in the righthand star wheel 34. As a consequence of further rotation of the shaft I6, the roller 35b for the right-hand link a in Fig. 1 will be cammed upwardly by star wheel 34, drawing up the link 3902 and rocking the shaft 29 clockwise from the position of Fig. 2'. This will result in pushing up the link 21 in Figs. 2 and 6 for the left-hand spool and disengaging this spool from the associated drivin rollerl1, thereby stopping the feeding of the ribbon. Due to the drawing up,- weirdly of the link a for the right-hand unit RH, the lever 23 therefor, will be rocked counterclockwise and wedge the right hand spool between its driving roller H and the right-hand roller 2i, thereby starting the winding of the ribbon on the right-hand spool.

These conditions. will be reversed when ultimatch, the left-hand spool becomes. empty, allow-ingits bell crank 3+ to rock clockwise and pushing roller 3% associated therewith. into the path of the teeth in the left-hand wheel 34. This will cause the link 3p in Fig. 2 to be pushed downwardly and the link 21 0!.- for the righthand unit will be pushed upwardly, thereby stopping the feedin of the ribbon on the. righthand spool.

If the operator, in installing a 18W ribbon wishes, to reverse the feed to insure that the ribbon immediately will start to feed in the. QIQPBI. direction, the lever Z8 may be pushed p or down as. he, case may he. to manually condition the ribbon. feeding mechanism for feedi g. i he prop d ec ion- The main a v n a t he; rib mecha sm is, the ease or remoyal; of the ribbon. It. is. merely necessary to push th lovers 32;, toward the rear of the me hanism o clockwise in. Fi 2 and lift 1. Spools out OI their pQokets.

While there. have been shown and. described and. p inted out. the un amental. novel, features of the. invention. as pplied to a preferred em? bodiment. it will be understood. that various. omissions. and substitutions and changes... in. the form. and details of the device illustrated and in its operation may b made-by those skilled in the, art without. departing, from the s irit. of the. inyention. It is the. intention. therefiore, to. be. lim t d only as. i dicated by the. soonest. the forlowing, claims.

What. s. laimed. is! j 1... A. ribbon. feeding mechanism. comprising a pair Qt ri bon spools, adri'veshait having. a frictiQnJdr vje. roller. for each, of. said. spoon, means ss c ted? w h. e h p ol. for eng in such spool with the associated drive. roller. means, interconnecting said" engaging means and movable between, two alternate positions in one ofj'whi'ch osition one spool is. engaged with and the other disengaged from the corresponding driving roller same and in the other of which positions these conditions are reversed, means to detect exhaustion of the ribbon, and means controlled by the detectioh means for shifting the interconnecting means to cause the exhausted spool to be driven by its roller and the other spool to be disconnected from its roller.

2. In a ribbon mechanism, a pair of ribbon spools, a frame work including a pair of pockets, one for each spool, each pocket having a fixed guide roller and a driving roller for rotatably supporting the spool, control means including a pair of elements, one for each spool for lifting the spools out of engagement with their driving rollers to allow the spools to unwind, said means being settable in alternate positions in each of which a different one of said spools feeds while the other unwinds, means to detect exhaustion of said spools, and means rendered operative by the detection means when any spool becomes exhausted, to actuate the control means to lift the fun spool from its driving roller and engage the exhausted spool with its driving roller.

3 A ribbon feeding mechanism for ofiice machines comprising a pair of ribbon spools; a pair of detecting devices, one for each spool, for detesting exhaustion of the associated spool; a pair of friction driving rollers, each associated with one of said spools; means to drive said rollers; a pair of coupling devices, one for each spool for engaging said ribbon spools with said rollers, said coupling devices being intercoupled so that when either coupling device is effective the other is ineffective; and a pair of shift devices, one for each spool and connected to the coupling device for such spool, each shift device being rendered effective by the detecting device of the associated spool, when the latter becomes exhausted, to actuate the associated coupling device to operative position.

4. A ribbon feeding mechanism for office machines comprising a pair of ribbon spools; a pair of detecting devices, one for each spool, for detecting exhaustion of the associated spool; a pair of friction driving rollers, each associated with one of said spools; means to drive said rollers; a pair of coupling devices, one associated with each spool, for engaging such spool with its driving roller, said devices being intercoupled so that rendering one effective renders the other ineffective, and a pair of shift devices, one for each spool, for rendering the associated coupling device effective, each shift device including a cam rotated by said driving means, and a normally ineffective cam follower rendered effective by the detecting device for the associated spool to enable the cam to set the coupling device for such spool in effective condition when such spool is exhausted.

5. A ribbon feeding mechanism comprising a pair of ribbon feeding units, each unit including a ribbon receptacle, a friction drive roller in said receptacle, a ribbon spool in said receptacle, a roller for supporting said ribbon spool, a control lever having a pair of rollers, one coacting with the supporting roller to hold the spool out of operation with said cam under control of said exhaustion detecting device when the ribbon spool becomes exhausted to enable said cam to actuate said lever-to active'po'sition; means to actuate the drive rollers and cams of both units, and means interconnecting said levers for, positioning the lever 'of the opposite spool in the inactive position when the lever for the exhausting spool is set in active position by its cam.

, 6. In a ribbon mechanism, a pair of ribbon spools, a frame work including a pair of pockets, one for each spool, each pocket having a fixed guide roller and a driving roller for rotatably supporting the spool; driving means for said driving rollers; control means including a pair of elements, one for each spool, for lifting the spools out of engagement with their driving rollers to allow the spools to unwind, said means being settable in alternate positions in each of which a different one of said spools feeds while the other unwinds, means to detect exhaustion of said spools, a pair of shift actuators one for each of said spools and actuated by the driving means, and means rendered operative by the detection means when any spool becomes exhausted, to couple the shift actuator for such spool to the control means for such spool whereby to disengage the full spool from its driving roller and engage the exhausted spool with its driving roller.

7. A ribbon feeding mechanism comprising a pair of ribbon spools, a drive shaft having driving members rotatably engaging the rims of said spools, means associated with each spool for engaging such spool with the associated driving member, means interconnecting said engaging means and movable between two alternate positions in one of which positions one spool is engaged with and the other disengaged from the corresponding driving member and in the other of which positions these conditions are reversed, means to detect exhaustion of the ribbon, and means controlled by the detection means for shifting the interconnecting means to cause the exhausted spool to be driven by its driving member and the other spool to be disconnected from its driving member.

8. A ribbon feeding mechanism for ofiice machines comprising a pair of ribbon spools; a pair of detecting devices, one for each spool, for detecting exhaustion of the associated spool; a pair of friction driving rollers, each associated with one of said spools; means to drive said rollers; a pair of devices, one associated with each spool, for bodily moving such spool into and out of engagement with its driving roller, said spool moving devices being intercoupled so that rendering one effective renders the other ineffective; and a pair of shift devices, one for each spool, for rendering the associated spool moving device effective, each shift device including a cam rotated by said driving means, and a normally ineffective cam follower rendered effective by the detecting device for the associated spool to enable the cam to set the spool moving device for such spool in effective condition when such spool is exhausted.

9. A ribbon feeding mechanism comprising a pair of ribbon feeding units, each unit including a ribbon spool, an exhaustion detecting device, a driving member, means to move the ribbon spool into and out of engagement with the driving member, and a shift device rendered effective by the exhaustion detecting device to actuate the spool moving means to move the ribbon spool 7 into engagement with the driving member when the ribbon spool is exhausted; means to drive said members and said shift devices, and means interconnecting said shift devices and spool moving means to render one spool moving means ineffective when the other is rendered effective.

10. A ribbon feeding mechanism comprising a pair of ribbon feeding units, eachunit including a ribbon receptacle, a rotary driving element in said receptacle, a ribbon spool in said receptacle, a control lever having a pair of rollers, one effective to hold the spool out of engagement with the rotary driving element when said lever is in an inactive position and the other roller coacting with the ribbon spool to hold the latter in driving relation with said driving element when said lever is shifted to an active position, an exhaustion detecting device for said spool, a shift actuator, and a coupling element normally out of cooperation with said actuator, and connected to said lever, said coupling element being shifted into cooperation with said actuator under control of said exhaustion detecting device when the ribbon spool becomes exhausted to enable said actuator to actuate said lever to active position; means to actuate the driving elements and actuators of both units, and means interconnecting said levers for positioning the lever of the opposite spool in inactive position when the lever for the exhausting spool is set in active position by its actuator.

CHESTER W. CRUMRINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 763,906 Kavle June 28, 1904 1,018,176 Ellis Feb. 20, 1912 1,065,769 Barrett June 24, 1913 1,257,401 Roebuck Feb. 26, 1918 1,848,508 Utz Mar. 8, 1932 

